Why do pear leaves turn black?

Why do pear leaves turn black?

It is very unpleasant for every gardener to see signs of damage by diseases or pests on a fruit tree. Unfortunately, fruit crops are a tasty and desirable food for parasites. Diseases and insects not only spoil the appearance of the crown, they significantly weaken the entire plant and, in the absence of proper measures, can even destroy the fruit tree. The article will consider the causes of blackening of foliage on a pear, as well as ways to eliminate it.

The reasons

Without a doubt, such external manifestations as curling, drying, blackening of the leaves and an unsightly appearance of the fruit clearly indicate problems. To help the pear tree cope with adversity, it is necessary to identify the source of the trouble. And this is not always easy, because there are not so few possible reasons. And the choice of the right treatment and assistance to the culture will depend on the accuracy of defining the problem.

Diseases

Often on a pear, the leaves turn black due to the defeat of the fruit tree by some disease. Dark or black spots on leaf blades are a visible sign of the development of fungal microorganisms or viruses. Therefore, in order to accurately determine the causes of pear disease, you need to familiarize yourself with other signs of the most common ailments of this culture.

Scab is a fungal infection. It quite often affects fruit trees, their leaves, fruits, branches. The fungus also likes to settle on young shoots, as they are very tender and vulnerable to attack by microorganisms.

First, foliage or fruits are affected by spores of the fungus. This is manifested in the appearance of light green spots. They do not differ much from the color of the leaf or the unripe yet green fruit. Therefore, often summer residents and gardeners do not immediately pay attention to them.

With the further development of this fungal disease, rounded spots of dark brown and black color appear on the leaf plates. They gradually grow and become more and more visible to the eye. After a short period, the leaves dry up and curl up, then fall off.

In summer, scab activity is highest in June and July. During this period, the crowns of mature trees and seedlings should be especially carefully examined. Young fragile foliage is usually affected first.

Scab is able to quickly spread to neighboring trees, especially when planted closely. The source of fungal infection is most often contaminated soil, last year's unharvested foliage, the fruits of diseased trees.

Another very common disease of pears is soot fungus. The microorganism feeds and multiplies on sugary secretions that are left by aphids, suckers or thrips.

We can say that these insects and the fungal microorganism work in a kind of tandem. Therefore, in order to effectively combat the disease, it is necessary to pay attention to the destruction of the above-mentioned pests.

On infected leaves, dark dots are not very noticeable at first. Their number is actively growing. Spot darkening expands and turns into very noticeable spots. Gradually, blackening captures the entire leaf or fruit of the pear.Outwardly, it looks like the foliage and fruits are covered with a coating of dark gray soot. This plaque is easily removed mechanically by rubbing a leaf or pear. But the removal of soot spots does not lead to a cure.

Moniliosis is a disease better known as "fruit rot". The disease develops on the fruits of apple and pear trees. Infected leaves and fruits are first covered with small brown spots. Over time, the entire leaf plate or pear fruit is covered with a dense dark bloom. The pulp of an infected fruit is not affected, but due to the disease it becomes almost tasteless, loose in structure, unsuitable for consumption.

Fruit rot can also develop on the branches of fruit trees. Over time, the development of the disease leads to their drying out and brittleness.

A serious disease of pear trees, poorly treatable, is a bacterial burn. At the initial stage of the disease, the edges and tips of the leaves turn black and dry. If there are fruits on the tree, then blackness also appears at their ends. The tissues of the leaves and fruits begin to die off quickly. The tree loses buds, ovaries, actively sheds foliage. Often the plant eventually dies.

Treatment of a bacterial burn is not effective in all cases. The fact is that this disease penetrates the sap flow system of the tree and spreads very quickly throughout all tissues of the plant.

Most often, young pears under the age of 10 years are affected by a bacterial infection. Their immune system is still very vulnerable, but at the same time, their internal metabolic processes are more active. These two factors make them victims of the disease.

Pests

Parasitic insects can be another reason for the weakened and unhealthy condition of pear trees.The peak of their activity occurs in the summer, so the traces of their vital activity are immediately visible to the eye by the condition of the leaves, young shoots and fruits.

Aphids are a real disaster for the garden. The insect is very voracious and causes huge damage to fruit trees. This parasite is activated already from early spring, at this time it feeds on buds and tender young leaves.

Signs of aphid vital activity become noticeable immediately. The leaves on the trees are twisted into a tube, their edges dry and darken. The insect especially loves to feast on developing young shoots. It is there that you can find the largest accumulation of individuals.

Aphids coexist in tandem with ants. They feed on the sugary secretions of the pest and often carry the larvae or adults of the aphid on them. So starting the fight against aphids, you should also get rid of anthills near fruit crops.

Copperhead significantly harms pear trees. This is a small flying insect that can quickly and easily move through the crowns. The pest prefers to feast on young shoots, shoots and succulent leaves.

Depleted leaves eventually dry out and fall off. The larvae of the pest during the development period secrete the so-called "copper dew". It is she who is visible to the eye as a dark coating on foliage, buds or fruits.

Another pest that affects pears is the leafworm insect. She settles on the leaves and tightens their edges, forming around herself something like a natural cocoon. Feeding on juice, the leafworm begins to actively lay eggs. The larvae that hatch from them also later eat the foliage.

When attacked by this parasite, the leaves first curl up, and after a while they turn black and fall off.Due to the fact that the foliage does not change color immediately, the first signs of damage to this harmful insect are not immediately evident. It is especially difficult to see curled, but not yet changed color leaves on tall and dense crowns.

The gall mite overwinters in the buds of the pear tree. With the advent of warm spring days, the insect actively lays eggs. The emerging larvae and adults settle on the blossoming foliage and begin to feed on its juices.

First, very light greenish spots appear on the leaves. During this period, inexperienced gardeners may not notice warning signs and miss time. Then pimples and turrets (galls) are formed on the leaf plates, in which tick colonies live. Neoplasms turn brown and blacken. Insects migrate from the galls to new areas, leaving a blackened and drying leaf. Outwardly, at this stage, the defeat of the gall mite can be confused with the scab attack.

The pest can be carried by animals, birds, wind. Often the source of the spread of the insect in the garden are new seedlings already affected by the parasite.

Mistakes in care

There are frequent cases when the blackening of foliage on a pear is a consequence of neglecting the rules of agricultural technology. In other words, improper care of the fruit crop can provoke a change in the color of the foliage.

Black leaves may indicate that the pear lacks moisture in the atmosphere. In this way, the tree reacts to extreme heat and prolonged dry weather. Also, pear foliage does not tolerate dust. In addition to additional watering, in this case it is worth taking care of spraying the crown with water.

Another reason leading to darkening of the foliage may be a lack of nutrients.The pear reacts especially painfully to a lack of calcium. With its deficiency, the leaf plates begin to darken from the middle to the top of the sheet. The situation is corrected by the introduction of calcium nitrate with irrigation.

If, simultaneously with the appearance of darkened leaves, deformation of young shoots is observed. This is a sign of boron deficiency. In this case, the plants should be sprayed with a weak solution of boric acid from a pharmacy.

Methods of treatment

Now it’s worth moving on to a description of specific methods that will help cure diseases and overcome pests.

In many cases, you will have to work with chemicals, so you need to remember the safety rules. Take care to prevent contact of solutions and preparations with exposed skin. The airway should be protected by a respirator or at least a tight gauze bandage.

It is necessary to combat the insidious and common disease of fruit crops - scab, in a complex manner. Affected leaves and fruits should be removed from the tree as soon as possible and burned or taken away from the site. In autumn, you need to carefully collect the fallen leaves, not leaving it under the pear tree for the winter. The means of control and prevention are also regular thinning of the crown and digging of the soil before winter.

In the spring, the pear is sprayed with Bordeaux liquid or karbofos. If during the summer the signs of the disease again made themselves felt, the preparations "Horus" and "Topaz" are used.

In most cases, treatment will have to be carried out throughout the season until the fungus is completely eliminated.

The fight against soot fungus should go in parallel with the destruction of the insects provoking its appearance - aphids and suckers. The fight against these and other pests will be discussed later in the article.

Fungal plaque itself can be treated with fungicidal compounds, for example, the drug "Skor". A safer method from the point of view of environmental friendliness is the use of products containing microorganisms that are hostile to soot fungus, and not chemical poisons. These include the compositions "EM 1", "Shine". The microbes contained in these preparations do not harm the pear tree, however, they actively absorb the sugary secretions of aphids and suckers. At the same time, the soot fungus loses its nutrition and stops its development on foliage and fruits.

Methods for getting rid of a disease such as moniliosis (fruit rot) are in many ways similar to the above measures to combat scab. In early spring, the crown must be treated with Bordeaux liquid. During the growing season, it is advisable to use the preparations "Topsin", "Fitosporin", "Folicur".

The most difficult to treat and insidious pear disease is the so-called bacterial burn. Its course is often quite rapid, and in many cases leads to the rapid death of even an adult tree. The transience and low percentage of cure are associated with the specifics of this disease. With a bacterial burn, harmful microorganisms penetrate the tree's sap flow system and act from the inside. Therefore, almost all systems and parts of the plant are simultaneously affected and rapidly weakening.

As a preventive measure and strengthening the protective forces of the fruit crop, in the spring the crown is sprayed with preparations containing copper. The treatment can be repeated several more times during the summer season.

All parts of the plant showing signs of disease should be removed. When cutting branches or sawing off knots, part of the healthy area adjacent to the infected should also be captured.All cut branches, knots and fruits are disposed of or burned.

Treatment consists of spraying the pear with antibiotics. The most commonly used broad-spectrum drug is Ofloxacin.

An innovative method for curing fruit crops from such diseases is the introduction of antibiotic solutions directly into the trunk. Thus, the antibiotic will go directly into the composition of tree sap. In this case, the antimicrobial drug is able to destroy a much larger number of viruses and bacteria walking through the plant's sap flow system.

However, it is worth noting, not without regret, that not in all cases the measures described lead to the successful cure of the pear tree.

Get rid of the invasion of aphids will have throughout the season. Usually the insect reappears on the foliage after precipitation. Ants often bring the larvae of this pest to the trunks and young shoots of fruit trees.

If the defeat of aphids is not too extensive, you can try more gentle folk methods. The most common and well-established is spraying the crown with an infusion of garlic with the addition of soap. Such methods of exterminating aphids are also common: treating the crown with a solution of stove ash (boil 300 g of ash for 30-40 minutes in 10 liters of water), ammonia (2-3 tablespoons of pharmaceutical ammonia in a bucket of water) infusion of tansy, wormwood, tops of tomatoes or tobacco (1 kg of the tops of any of the listed plants, pour a bucket of water heated to 38-40 degrees, leave for at least 3 hours, strain).

In all these sprays, you need to add liquid soap or dissolve household shavings. The soap solution lingers better on the leaves, does not evaporate for a long time.In addition, the soapy liquid envelops the bodies of the aphid and its larvae, making it impossible for them to breathe through the pores.

Spraying is repeated after 8-10 days or after the last rain.

It is necessary to exterminate the sucker from the period of bud break. The branches and trunk are sprayed with a kerosene solution. It includes 40-50 g of laundry soap shavings, 80 g of kerosene. The components are dissolved in 10 liters of water. The composition allows you to destroy a significant percentage of overwintered insects.

After the blooming of young leaves, treatment with a solution of karphobos (concentration 0.2%) is carried out. The same tool is processed in early September, after the removal of the fruit.

As in the fight against aphids, folk methods are very effective: treating the crown with infusion of ash or tobacco leaves.

The leaflet will have to be exterminated with insecticides (Fitoverm, Fuzanon). Spraying is repeated with a break of 2-3 weeks. To prevent the spread of the pest in early spring, seedlings and the crown of adult trees can be treated with Fitoverm.

So-called acaricides are used to combat gall mite colonies. The foliage of the affected fruit tree is sprayed for at least two months every two weeks.

From folk recipes, as an aid, you can use a decoction of marigolds (boil 100 g of the plant in a liter of water, cool, add liquid or laundry soap), dandelions, potato tops (prepared in a similar way).

Prevention

Any disease is better to prevent than to cure. The same principle is quite fair and appropriate for fruit crops. The following preventive measures will help to avoid the spread of pests and diseases:

  • annual pruning of branches for the purpose of thinning the crown;
  • compliance with agricultural technology;
  • ensuring sufficient watering and spraying foliage with water in dry weather;
  • carrying out a full feeding of plants in the spring;
  • cleaning the near-stem zone from weeds, fallen leaves and fruits;
  • annual autumn digging of the soil under the crown of a tree;
  • timely treatment of diseases and the fight against pests found on the pear;
  • cuttings for grafting should not be taken from infected plants;
  • do not purchase seedlings with signs of disease or pest activity.

A tree weakened by insect attacks and diseases is less resistant to the factors described above, leading to blackening of the leaves.

Helpful Hints

At the end of the article, it would be useful to give advice and recommendations from experienced gardeners. They will complement the main methods of combating diseases and parasitic insects:

  • After pruning, experienced gardeners are not too lazy to disinfect all used tools. The working surfaces of the secateurs or scissors are wiped with alcohol or they are calcined on fire.
  • Spraying of plants should be carried out in the evening, after the heat has subsided, in dry, calm weather.
  • Well strengthens the immune system of the tree and stimulates its vegetation by regular loosening of the soil in the near-stem zone. It is especially important to systematically carry out such a procedure in the first years of the life of young seedlings.
  • The trunk of mature trees must be cleaned of dead bark. Between its drying parts, insect pests are very fond of nesting and laying eggs. And decaying areas serve as a breeding ground for harmful microflora and fungus.
  • Prevention of the spread of many diseases and pests is the whitewashing of fruit tree trunks.

About why the leaves on the pear turn black, the causes and methods of treatment are shown in the following video.

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The information is provided for reference purposes. Do not self-medicate. For health issues, always consult a specialist.

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